Alarms in ClearSCADA can be redirected to SMS messages and may be acknowledged via an SMS response. Getting this functionality to work however can be quite tricky. The purpose of this article is to point out some general information on getting this feature working.

There is a pseudo list of supported devices which is not in any way inclusive, these are just devices that have been noted as working. Siemens TC35 Wavecom WMD02 - Now Sierra Wireless, model unknown TIXI H620 Multi-Tech Multimodem GPRS For a modem to work it must support at a minimum GSM 07.07/3GPP TS 27.007 AT command set

For SMS alarming to work correctly a GSM standalone modem MUST be used. Sending SMS via E-Mail will fail in most cases.

Generally speaking the basic configuration in ClearSCADA is as follows.

1. A Pager Action is triggered by an alarm redirection from a point. This actions specifies the message and the user whom to send the message to
2. The User configuration specifies a Pager Service. This Pager Service setting points to an SMS Pager Service which specifies the message coding and other general settings.
3. The SMS Pager Service is associated with an SMS Pager Channel which specifies the connection to the modem.

There are a few common stumbling blocks associated with this sort of setup.

1. The modem in question must support some specific commands. Below is a screenshot of a successful modem initialization. It should be assumed that if a modem does not support these commands things will not function properly.
   
2. Allowing commands to be issued via SMS is required.
   
3. When a txt message arrives to ClearSCADA it must first associate that message with a user in the database to check for permissions. The only way ClearSCADA can do this is my checking the phone number which is received with the txt message against what is specified for the users. It is EXTREMELY IMPORTANT to note that most of the time mobile numbers will appear with a "+", a "1" and the area code in them. If for example a user is configured to send text messages to a phone number 960 555 5555 in all likelihood when a response arrives back the number in the Pager log file will look like +1 960 555 5555. In this case the message will fail because ClearSCADA did not find any user with the number +1 960 555 5555. In this case ClearSCADA usually logs an alarm which indicates SMS message received but from an unknown user. The solution is to always put +1 in front of all phone numbers in ClearSCADA.
4. To acknowledge an alarm the response txt message must contain one of two following methods:
   • $Root.AcceptAlarmByCookie(nnn)      Where nnn is the cookie number of the alarm. Cookie number may be sent in the SMS with the %ACookie% trip sequence
   • Full path of point.Accept()     This method however accepts ALL alarms associated with the point